Studying an exceptionally rare Elite Aging population is the logical perspective for a new phase of the BLSA. By including participants with IDEAL characteristics, the BLSA will be able to utilize fully the extensive set of measures that have been recently introduced in the study. In addition, the study of IDEAL aging is in keeping with the original mission of the BLSA concerning the study of healthy aging, independent of the effect of disease. There is no perfect control group available for the Elite Aging. Theoretically, the ideal group would be people born in the same year who would have the same demographic characteristics as the highly IDEAL Aging individuals, who were studied at a younger age, and then died or become sick or disabled before the age of 80. Researchers studying centenarians have struggled with the issue of the ideal control group and controversy remains over this challenge. A possible alternative is to use an existing cohort that was born approximately the same time as the IDEAL Aging individuals, already enrolled in the study , and that have been documented to have died or become disabled. Current BLSA active participants 80 years or older (n=482;282 men and 200 women) provide very good controls for the Elite group. In fact, although they belong to the same age cohort as the IDEAL Aging cohort, most are no longer healthy and the few who qualify for the Elite Aging cohort would not be included in the control group . By entering the IDEAL cohort in the full BLSA assessment, their biologic, physiologic, behavioral and functional characteristics will be evaluated with exactly the same methods used with the currently active cohort, both expanding the values of the BLSA and allowing an economy of scale. We began enrolling into the BLSA individuals who have already reached the goal of healthy longevity (IDEAL cohort) and to compare them with current BLSA participants who were no longer healthy or fully functional when they reached the age of eighty years. As it is customary in the BLSA, we plan to follow this cohort for life with yearly visits. The first aim of this study is to identify factors and characteristics that distinguish IDEAL from non IDEAL individuals. In the current BLSA, an extraordinarily wide rage of information is collected on biomarkers, physiological measures, behavioral and environmental risk factors and functional and disease-related outcomes. We propose to collect the same information in the newly enrolled IDEAL aging cohort and to compare the two groups to identify factors that discriminate IDEAL aging from non IDEAL aging individuals. The second aim is to identify physiological, environmental and behavioral characteristics that are risk factors for losing the IDEAL condition over several years or longer. We postulate that the mechanisms of extreme longevity are probably different from those associated with delay or escape from disease and disability. For example, it may be hypothesized that in older persons who escape diseases and disability, homeostatic mechanisms (integrity of anti-oxidant mechanisms, low level of oxidative damage to macromolecules, low inflammation, unimpaired autonomic reflexes, normal hormone levels etc.) should be relatively intact, with little accumulated damage. Of note, the BLSA is the ideal cohort in which to conduct this research because state-of-the-art measures of these mechanisms have been already piloted and implemented. For operative purposes, IDEAL Aging will be considered individuals 80 years or older who meet the current BLSA inclusion criteria for healthy aging. It can be conservatively estimated that approximately 1% of those 80 years or older are IDEAL Aging individuals. IDEAL subjects will be recruited from the Baltiore-Washington area, whick has catchment population of about 15 million people. We estimate that about 6,000 of these should be IDEAL candidates. Once IDEAL individuals are included in the BLSA, they will receive the same set of assemements received by all BLSA participants, which include a large number of physiological measures, biomarkers of aging and diseases, biomarkers of homeostasis, health behaviors, cognition and mood, Socio-economic and educational status (See the BLSA project). It is postulated that these measure will allow discrimination between IDEAL individuals, and age-matched BLSA participants who were healthy at study entry, but during the course of the study developed diseases and disability. The longitudinal follow-up of the IDEAL individuals may reveal risk factor for health decline at the extreme portion of the age spectrum in exceptionally healthy individuals. The enrollment of IDEAL participants in the BLSA will be conducted under and R&D contract, which has been already assigned to WESTAT. We are currently in the phase of obtaining OMB clearance. It is expected that this contract will be assigned over the next few months.